Electronic devices such as computers and peripheral equipment generally have at least one onboard electrical connector which serves as an input/output (I/O) port for the device. The I/O connector typically has a shield or shell which is grounded to the chassis of the electronic device for protecting the device against electromagnetic interference and against electrostatic discharge when the device is interconnected with another device by an interconnect cable. However, one of the devices to be connected may be at an elevated ground potential with respect to the other device. Therefore, the devices need to be protected against low frequency current that would flow therebetween due to the unequal ground potential during mating and unmating of the interconnect cable. Each device can be protected by a capacitive coupling between the I/O connector and the chassis of the device which would block passage of low frequency current. The invention provides an I/O connector having a capacitive coupling for protecting against low frequency current.